Researchers Accidentally Discovered an Ancient Megacity in a Mexican Jungle

Lidar technology is revealing that the Mayan civilization was more complex and interconnected than previously thought.

Katarina Hall | From the May 2025 issue



(Photo: Maya archaeological site in Calakmul, Mexico; Philip Dumas/Getty)

In 2024, a Mayan megacity was discovered in Campeche, Mexico. Swallowed by the rainforest, this lost urban center contained pyramids, plazas, amphitheaters, and highways. But this discovery wasn't made by a team of seasoned explorers hacking through the rainforest with machetes. It was made by a Ph.D. student. And he found it by accident.

"I was on something like page 16 of a Google search and found a laser survey done by a Mexican organization for environmental monitoring," Luke Auld-Thomas, who is pursuing his doctorate at Tulane University, explained to the BBC in October. That overlooked, decade-old survey contained groundbreaking information hidden in plain sight.

The survey used light detection and ranging (lidar) technology, a remote-sensing method that sends thousands of laser pulses from an aircraft to map objects buried beneath vegetation. The system measures how long it takes for the signals to bounce back, creating a detailed 3D image of the landscape.

Now named Valeriana, this lost metropolis is believed to be one of the densest Mayan cities ever discovered. At its peak (between 740 and 850 A.D.), it may have housed anywhere from 30,000 to 50,000 people—more than the region's population today. Over 6,000 buildings were identified, ranging from homes to towering pyramids. "The larger of Valeriana's two monumental precincts has all the hallmarks of a classic Mayan political capital: enclosed plazas connected by a broad causeway; temple pyramids; a ball court; a reservoir formed by damming an arroyo (a seasonal watercourse)," said Auld-Thomas in findings published in the journal Antiquity.

More:
https://reason.com/2025/04/27/lost-cities-in-the-jungle/